Results obtained with AI in Africander and Jersey cows under extensive conditions in the Northern Cape
AI was practised in a herd of approximately 270Africander and 75 Jersey cattle over a five year period at Vaalharts Research Station. During the annual two and a half month breeding period 80,3% of 1297 Africander and 94,7% of 357 Jersey cattle were inseminated. Of those inseminated in the Africander, 55,4% conceived, being 44,5% of the total number available. Corresponding conception rates obtained in the Jersey were 71,0% and 67,2% respectively. In the Africander the average number of services required per conception was 3,75 cf . 3,23 in the Jersey. These figures include a double insemination on first estrus practised during one breeding season. During the same five year period 360 Africander and 78 Jersey cows were also put to the bull. Conception rates obtained were 85,8% and 78,2% for the two breeds respectively. Although a lower percentage of lactating Africander cows exhibited oestrus, a considerably higher conception rate on first inseminations was obtained in comparison to both dry cows and heifers. In the Jersey,the best results in this respect were obtained in heifers while lactating cows again outperformed dry cows .The practise of a double insemination on first oestrus increased the average conception rate from 34,5% to 43,2% in the Africander and from 34,7% to 47.9% in the Jersey.